
\begin{tikzpicture}[scale=1.5]
  \tkzDefPoints{-2/0/A,-sqrt(2)/sqrt(2)/B,2/0/C,0/0/D}
  \tkzDrawPolygon(A,B,C)
  \tkzDrawSegment(B,D)
  \tkzMarkSegments[color=teal,mark=|](A,D C,D)
  \tkzLabelAngle[pos=.5](B,D,A){$45^\circ$}
  \tkzDrawPoints(A,B,C,D)
  \tkzLabelPoints[below](A,C,D)
  \tkzLabelPoints[above](B)
\end{tikzpicture}
